List of Hot 100 number-one singles of 2020 (Japan)
# List of Hot 100 number-one singles of 2020 (Japan)

The following is a list of number-one singles on the Billboard Japan Hot 100 chart in 2020.

## Chart history

| Issue date | Song | Artist(s) |
| - | - | - |
| January 6 | "Pretender" | Official Hige Dandism |
| January 13 | "Pretender" | Official Hige Dandism |
| January 20 | "Pretender" | Official Hige Dandism |
| January 27 | "Sōyūtoko Aru yo ne?" | SKE48 |
| February 3 | "Imitation Rain" | SixTones |
| February 10 | "Mubō na Yume wa Sameru Koto ga Nai" | STU48 |
| February 17 | "I Love..." | Official Hige Dandism |
| February 24 | "I Love..." | Official Hige Dandism |
| March 2 | "Sonna Koto Nai yo" | Hinatazaka46 |
| March 9 | "I Am" | Hey! Say! JUMP |
| March 16 | "Infinity" | JO1 |
| March 23 | "I Love..." | Official Hige Dandism |
| March 30 | "Shitsuren, Arigatō" | AKB48 |
| April 6 | "Shiawase no Hogoshoku" | Nogizaka46 |
| April 13 | "Fallin' Flower" | Seventeen |
| April 20 | "I Love..." | Official Hige Dandism |
| April 27 | "I Love..." | Official Hige Dandism |
| May 4 | "3-2" | HKT48 |
| May 11 | "I Love..." | Official Hige Dandism |
| May 18 | "I Love..." | Official Hige Dandism |
| May 25 | "Kōsui" | Eito |
| June 1 | "Yoru ni Kakeru" | Yoasobi |
| June 8 | "Yoru ni Kakeru" | Yoasobi |
| June 15 | "Yoru ni Kakeru" | Yoasobi |
| June 22 | "Mazy Night" | King & Prince |
| June 29 | "Kanzai Boya" | KinKi Kids |
| July 6 | "Shōko" | Johnny's West |
| July 13 | "Last Mermaid..." | Hey! Say! JUMP |
| July 20 | "Fanfare" | Twice |
| July 27 | "Yoru ni Kakeru" | Yoasobi |
| August 3 | "Navigator" | SixTones |
| August 10 | "Kite" | Arashi |
| August 17 | "Run" | Sexy Zone |
| August 24 | "Smile" | Twenty Twenty |
| August 31 | "Re:Live" | Kanjani Eight |
| September 7 | "Oh-Eh-Oh" | JO1 |
| September 14 | "Omoidaseru Koi wo Shiyō" | STU48 |
| September 21 | "Yoru ni Kakeru" | Yoasobi |
| September 28 | "Endless Summer" | Kis-My-Ft2 |
| October 5 | "Yoru ni Kakeru" | Yoasobi |
| October 12 | "Your Song" | Hey! Say! JUMP |
| October 19 | "Kissin' My Lips" | Snow Man |
| October 26 | "Homura" | LiSA |
| November 2 | "Homura" | LiSA |
| November 9 | "Homura" | LiSA |
| November 16 | "Homura" | LiSA |
| November 23 | "New Era" | SixTones |
| November 30 | "Homura" | LiSA |
| December 7 | "Homura" | LiSA |
| December 14 | "Step and a Step" | NiziU |
| December 21 | "Nobody's Fault" | Sakurazaka46 |
| December 28 | "I Promise" | King & Prince |
